Karl pauli billner



K. P. BILLNER. FIERROCONCRETE FLOOR CONSTRUCTION.

APPLICATION FILED JAN. 2l. I9IB.

Patented June 17, 1919'.

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.used for new cupolas.

KARL PAULI BILLNER, OF MALMO, SWEDEN.

FERROCON CRETE FLOOR CONSTRUCTION.

Speccation of Letters Patent.

Patented June 17, 1919.

Application led January 21, 1918. Serial N o. 213,044.

To all whom it 'may concern:

Be it known that I, KARL PAULI BILLNER, a citizen of Sweden, residing at Malmo, Sweden, have invented certain new and useful Improvements in Ferroconcrete Floor Construction, of which the following is a specification.

This invention relates to a ferro-concrete floor the substantial supporting parts of which are circular or elliptical cupolas, said floor being erected upon walls or girders in such a way that each cupola covers a large surface, for instance a whole floor without the use of any girders excepting the supporting beams at the edges of the cupola. Thus the cupola proper forms a substitute for the girders hitherto used in concrete floor constructions. Evidently a Hoor ac-` cording to the present invention is not to be compared with concrete floors consisting of girders with arches or slabs of one kind or another between said girders nor any other type of concrete floor construction.

The object of the invention is to provide a concrete floor having the advantage over concrete floors hitherto used that it can be made lighter than other floorings when large spans are used and that concrete of a poor mixture, for instance 1:5 :7, can be used, as with a thickness of the cupolas of for instance 6 centimeters the stress of the concrete does not exceed 10 kilograms per square centimeter at normal load. 0n account of the low unit stress amounting to only about 2 kilograms per square centimeter for the sole weight of the cupola the molds may be removed shortly after the molding of the cupola, for instance after 2 or 3 days, whereafter the molds may be Furthermore, the new invention causes a great saving of material and in many cases a line appearance may be given to the under side of the cupola without the use of plastering, if nicely constructed sheet molds are used.

The invention isillustrated in the accompanying drawing.

Figure 1 is a plan view of two cupola floors. Fig. Qcis a vertical section on the line A-A in Fig. 1, and Fig. 3 is a section of one of the floors on the line B-B in Fig. 1.

For the construction of a cupola floor of this type suitable molds of one kind or another are used and the reinforced concrete cupolas are given a circular or elliptical form according to the size and the form of the floor, and they are built up in such a Way that their circumference rests upon walls or girders 2. When a square or rectangular floor is to be erected beams 3 are placed obliquely in the corners of the room at the circumference of the cupola, said beams aiding to support the same, and the parts at the corners not covered by the cupola are covered with concrete slabs 1 which may be integral with the cupola or formed' therewith. The thickness of the ioor of the construction described may appropriately correspond to the usual thickness of hollow tile reinforced concrete constructions up to a span of 5v meters and it might be made somewhat thicker in larger spans. The concrete cupolas are reinforced in a suitable manner, for instance by means o'f concentric and radial reinforcement indicated at 6. A light heat insulating material 5 is lled upon and between the cupolas in such a way that a horizontal upper surface is obtained.

Floors of the type described are adapted for use in dwelling-houses, store-houses and particularly as a flooring over large rooms where supporting columns are not desired, such as theaters and assembly rooms, though they may be used in all kinds of buildings. Compared with for instance hollow tile reinforced concrete floors a cupola floor of the type described is much lighter and nearly 50% cheaper on account of cheaper material and reinforcement.

Having thus described my invention, I

claim and desire to secure by Letters` Patent A floor construction, comprising a plate having its central portion `spherically formed the convex side thereof being arranged uppermost, and substantially fiat triangular corners disposed outwardly of the spherical portion; a reinforcing rib formed upon the upper surface of the plate and surrounding the central spherical portion at the edge thereof; diagonal-reinforcing bars extending over the reinforcing ribs and the flat triangular corners and projecting above Jehe sanne for a substantial dis- 11eme to this specification in the presence of tance; `and e iiller disposed upon the upper' two subscribing Witnesses.

surface of the plete to provide :L Het surface and covering the spherical portion and KARL PAULI BLLNER' 5 having the reinforcingl rib and hers em- Vitnesses:

bedded therein. A. W. ANDERSON, In testimony whereof, I have signed my HJ. BRANZELL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

